I have no idea what happened everything else is really happy. But the polyps of both of them was just stuck around the skeleton. So I cut them off... and iodine dipped it just to be safe.... quite frustrated had those 2 for a year. All parameters were bang on. Even got 8.4 pH now since I ran a tube outside. For the skimmer. Everything was going really well. And out of the blue lost one of my favourite corals